Unique symptoms of brief (one to four second) recurring episodes of torsional diplopia with tremorous sensations in one eye, shimmering oscillopsia, or both, and uniocular signs of a high frequency (12 to 15 per second), pendular, low amplitude (1 to 20) vertical and rotary microtremor began spontaneously and persisted as a stereotyped ocular stabilization defect in five healthy adults (ages 23 to 45). Periodic intorsion of the affected eye and rapid phasic electromyographic activity in a superior oblique, and the absence of reciprocal phasic inhibition in its antagonist, suggested a nuclear (brain stem) disorder. The report describes the phenomenology and natural history of this symptomatically obtrusive, but previously undefined, benign myokymia-like syndrome of the superior oblique muscle.
Hoyt WF, Keane JR. Superior Oblique MyokymiaReport and Discussion on Five Cases of Benign Intermittent Uniocular Microtremor. Arch Ophthalmol. 1970;84(4):461-467. doi:10.1001/archopht.1970.00990040463011